at the Surface of the Terrestrial Globe. 393 



a different assemblage. Nevertheless, notwithstanding this 

 unity in the general plan, the greatest diversity prevails in its 

 development : the vertebrata of the first epoch are fishes, and 

 fishes only, associated with Articulata, with Mollusca, and 

 with Radiata, of species differing from those which presented 

 themselves afterwards. Thus we may regard this first age 

 as characterised by the rei^n of fishes. 



During the secondary epoch, it was no longer the inhabi- 

 tants of water which alone peopled the submerged surface of 

 the earth ; the class of reptiles appeared with a cortege of 

 Articulata, of Mollusca, and of Radiata unknown in the pre- 

 ceding age, and the fishes of this second great epoch assumed 

 a character which those of the first did not at all possess. 

 Strange monsters, of fantastic form, and of gigantic size, bring- 

 ing to our minds the fabulous dragons and harpies, then 

 peopled the sea and the earth ; and although some beings of 

 a superior organization had already begun to shew themselves, 

 the epoch of the secondary formations may be characterized 

 as the reign of reptiles. 



At the same time a vegetation, of which none of the various 

 floras of our epoch can give us a just idea, was developed 

 during that remote period. 



If we pass to the examination of the tertiary formations, the 

 scene at once changes. Numerous mammifera, heavy pachy- 

 dermata, ruminants of colossal forms, singular cetacea, and 

 birds, besides reptiles and fishes more and more resembling 

 those which live at the present day, without, however, being 

 identical with them, form the varied fauna of this epoch. A 

 rich vegetation was distributed over a more diversified sur- 

 face, but was still shared unequally by the solid land and the 

 ocean. The climate was more varied than formerly. This 

 was the reign of the mammifera. 



Corresponding with these changes in the nature of organ- 

 ised beings, others took place in the aspect of the surface of 

 our globe. Every thing leads us to believe that after the 

 consolidation of a first crust, when the waters had begun 

 to accumulate at its surface, our earth did not at all exhibit 

 in its relief the inequalities which we now see. It is, in fact, 



VOL. XXXIII. NO LXVI. OCTOBER 1842. C C 



